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Effect of Prazosin on Neurophysiology and Cognition in Post-Traumatic Stress Disorder (PTSD)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00890643
Recruitment Status : Withdrawn (Primary investigator left VA employment)
First Posted : April 30, 2009
Last Update Posted : September 23, 2013
Information provided by (Responsible Party):
VA Office of Research and Development ( US Department of Veterans Affairs )

Brief Summary:
In this study, the investigators are looking at how PTSD affects things such as memory, attention, reaction to sounds, eye movements, and heart rate. The investigators are also studying whether a medication called prazosin has an effect on these things.

Condition or disease Intervention/treatment Phase
Posttraumatic Stress Disorder Drug: prazosin hydrochloride Drug: placebo Not Applicable

Detailed Description:
Converging lines of evidence suggest that central nor adrenergic function is perturbed in PTSD. Placebo-controlled trials demonstrate that the centrally acting alpha-1 antagonist prazosin is clinically effective for several core symptoms of PTSD in combat veterans. However, no detailed assessment of the impact of prazosin on human neurophysiology and cognition have been conducted. Our hypotheses are based on studies that demonstrate (1) the importance of central adrenergic receptors in regulating fundamental neurophysiologic and cognitive functions, (2) the alteration of these functions in PTSD, and (3) the efficacy of prazosin in improving the clinical symptoms of PTSD. The primary objective of this study is to measure the subtle neurocognitive and neurophysiologic effects on prazosin in combat veterans with PTSD.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 0 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double
Primary Purpose: Basic Science
Official Title: Effect of Prazosin on Neurophysiologic Responses and Cognitive Performance in PTSD
Study Start Date : December 2009
Actual Primary Completion Date : June 2011
Actual Study Completion Date : September 2011

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Arm 1
Persons with PTSD
Drug: prazosin hydrochloride
prazosin 1-20 mg/day in divided doses
Other Name: Minipress

Placebo Comparator: Arm 2
Persons with PTSD
Drug: placebo

Primary Outcome Measures :
  1. Responses to acoustic startle and prepulse inhibition of acoustic startle [ Time Frame: baseline, week 2, week 8 ]

Secondary Outcome Measures :
  1. Heart rate variability [ Time Frame: baseline, week 2, week 8 ]
  2. Pennsylvania Computerized Neurocognitive Battery (CNB) [ Time Frame: baseline, week 8 ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Exposure to one or more life-threatening war zone trauma events;
  • DSM-IV diagnosis of PTSD derived from the Clinician-Administered PTSD Scale (CAPS), CAPS total score greater than or equal to 50;
  • CAPS recurrent distressing dreams item score greater than or equal to 5 (of a maximum score of 8), with a frequency rating greater than or equal to 2 (of 4);
  • stable dose of non-exclusionary medications and psychotherapeutic treatment for at least 4 weeks prior to randomization;
  • good general medical health;
  • female participants must agree to use a reliable form of birth control throughout study.

Exclusion Criteria:

  • Acute or unstable chronic medical illness;
  • diagnosis of current schizophrenia, schizoaffective disorder, psychotic disorder not otherwise specified, bipolar disorder, delirium, or cognitive disorder;
  • severe psychiatric instability or severe situational life crises;
  • substance dependence disorder currently or in past 3 months;
  • current cocaine or stimulant abuse or evidence of acute intoxication on alcohol or nonprescribed medication;
  • allergy or previous adverse reaction to prazosin or other alpha-1 adrenergic antagonists;
  • serious head injury with loss of consciousness of greater than 30 minutes;
  • current diagnosis of seizure disorder;
  • current use of prazosin or other alpha-1 adrenergic antagonists;
  • current use of atypical antipsychotic medication;
  • stimulants or alternative medications with stimulant properties (e.g. ephedra), certain exposure therapies must be completed at least 4 weeks before baseline;
  • certain medications (trazodone, erectile disfunction medications) are not allowed or are restricted during the study;
  • women must not be pregnant or nursing during the study.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00890643

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United States, Washington
VA Puget Sound Health Care System
Seattle, Washington, United States, 98109
Sponsors and Collaborators
US Department of Veterans Affairs
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Principal Investigator: Dorcas J. Dobie, MD VA Puget Sound Health Care System
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Responsible Party: US Department of Veterans Affairs Identifier: NCT00890643    
Other Study ID Numbers: MHBA-018-08S
First Posted: April 30, 2009    Key Record Dates
Last Update Posted: September 23, 2013
Last Verified: September 2013
Keywords provided by VA Office of Research and Development ( US Department of Veterans Affairs ):
Stress disorders, post-traumatic
Combat Disorders
Additional relevant MeSH terms:
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Stress Disorders, Traumatic
Stress Disorders, Post-Traumatic
Pathologic Processes
Trauma and Stressor Related Disorders
Mental Disorders
Antihypertensive Agents
Adrenergic alpha-1 Receptor Antagonists
Adrenergic alpha-Antagonists
Adrenergic Antagonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs